Primary divisibility of the protolithosphere and current tectonic divisibility of lithospheric blocks: New reconstructions

Abstract

The layer forming the Earth’s solid cover is considered to be a uniformly cooling mantle body of low viscosity involved in the convection process. Its cooling is accompanied by the formation of Rayleigh–Benard cells transformed into primary blocks. Their dimensions and dynamics in the subsequent evolution of the Earth’s lithosphere were repeatedly disturbed by superglobal geodynamic cycles involving changes in the area and dynamics of the blocks, some of which were partially absorbed by the mantle, while others were generated for the first time up to the current state. The variably ranked lithosphere blocks transformed into linear dimensions were arranged in a logical series of lithosphere destruction: from convection of the cooling Earth and initial block divisibility of the protolithosphere to its recent plate tectonics and intensive variably ranked fragmentation and fracturing of the plates under the conditions of solid body fragmentation. Convection in the mantle is a genetic endogenic source of the first protolithosphere divisibility. Megablock and subsequent lithosphere divisibility are consistent with the process of crushing of a solid body.